In his book The Frood: the Authorised and Very Official History of Douglas Adams and the Hitchhikers Guide to the Galaxy (published by Random House) Jem Roberts examines Adams' most beloved creation with the knowledge and affection of a true fan.

Mr Roberts, a writer and British comedy historian, brings together the fruits of exclusive forays into the Douglas Adams archive at Cambridge, and new interviews from friends and colleagues for a fresh take on Adams and his works, as he tells Kathryn Ryan.